Drive mechanism for windshield wipers



Oct. Z2, 1940. A, J. RICHARDS DRIVE MEcHAmsM FOR wINDsHmLD wIPERs Filedootjl, 1957' 2 sheets-sheet 1 .l Suventor /'cazra/s (Ittornegs Oct. 22,1940.A

A. .J. RICHARDS DRIVE MECHANISM FOR WLNDSHIELD -WIPERS Filed oct; 13,l1957' 2 -sheets-sheen? ngi; w11@ krymj Planta oa. 22,1946

UNITED fsrrATits@v PATENT orifice s 2,213,219` l" y v DRIVE MEcHANIsMFon. wmns'mELD wlrEns Arthur J. Richards, Detroit, Mich. Applicationoctober 13, 1937, serial 10.168.729

3 Claims:

This invention relates to mechanism for imparting a to and from oroscillatory movement, land more particularly to means fordriving awindshield wiper or other device having a similar 5 movement.

An object of the invention is to provide a very compact device of simpleconstruction which may be manufactured at limited cost and which deviceis particularly adapted for use upon motor vehicles employing internalcombustion engines as the motive power, the present device beingcharacter which is so constructed as to eliminate the noise ofoperation, and prevent leakage and loss of vacuum, the bellows being soarranged as to provide sealing means to prevent loss of vacuum, and thenoise of operation being eliminated by mounting the vvalve operatingmechanism within the casing between the adjacent ends of the bellows. Itis also an object to provide simple and quick acting valve mechanismwhereby the valve is operated with a snap action to quickly shift thevalve fromone position to another and wherein this action is effectedthrough the alternatey movement of the bellows pistons;

A further object is to provide certain other new and useful features inthe construction, arrange- 40 ment and combination of parts, all ashereinafter more fully described, reference being had to theaccompanying drawings in which l Figure l is a longitudinalsectionsubstantially upon the line I--I of Fig. 3 of a device illus-vFig. 3 is a transverse section substantially upon the line 3-3 of Fig.1; I

Fig. 4is a se tional detail substantially upon the line 4--4 of Fig. 3;

Fig. 5 is a sectional detail substantially upon 5 the line 5-5 of Fig.1, and

Fig, 6 is a transverse section substantially upon the line 6--6' of,Fig.v 1 andl drawn to a reduced scale.

vAs shown, the device comprises a suitable cas- 10 ing indicated as awhole by the numeral I and this case is formed with an outstandingannular rib 2 at each end. Sheet metal cylinders 3 are each formed upfrom a single sheet of metal with a continuous head or end and anoutstanding 15 ange 4 at the base or inner end of the cylinder. Each ofthese flanges is formed over a rib 2 on the case I to firmly attach thecylinders to the case in opposed relation to each other. y

Within each cylinder 3 is a piston 5, each piston being formed of rubberor other flexible material laid in folds or corrugations to provide abellows construction for ready expansion and contraction in thedirection of the length of the piston. The inner or base end of eachpiston wall 5 is formed 25 with an outwardly extending annular` ange 6which anges are adapted to be interposed between the ribs 2 of the caseI and the flanges 4 of the ends of the cylinders 3 so that each pistonis iirmlyanchored at its inner or open end 3o to an end of the case Iand its ange 6 forms a seal to tightly close the inner ends of thecylinders 3, the edge portion of Veach flange 4 bei-ng formed overv andturned inwardly against the inner sides of the ribs or flanges 2, thusvcompressing the rubber of the flanges 6 `between the ends of thecylinders 3A and the ends of thev case I to seal the piston and thecylinders against leakage. Y

The outer end of'each bellows 5 is closed by o a metal head comprisingan inner'metal diskl, an outer disk 8 andy an interposed sheet metaldisk 9,'the latter being formed with radially extending lugs I0 whichare bent laterally and longitudinally of the cylinder wall to engagesaid 5 wall and guide the piston within said cylinder. The disks 8 and 9are offset 'inwardly fromI their peripheries to provide a space betweenvthe disk 9 and the disk 1. within which space the end edge portion ofthe rubberwall of vthe"bellows'-is re'- 50 ceived to rmly securethe-bellows to the piston head and prevent any leakageof airfrom theinteriorv of the bellows toits exterioror into the chamber I I withineach cylinder ext'eriorly of the bellows piston. -Thechamber or space I2within 55 each bellows or the interior of each piston is in opencommunication with the chamber of the case I, the wall of which case isprovided with a plurality of openings I4 which are open tothe outsideatmosphere and therefore the interior of each bellows piston is underatmospheric pressure at all times. The disks 1, 8 and 9 forming the endsor heads of the bellows'pistons are firmly clamped together by axialrivets I4a and these rivets also serve to rigidly secure the upwardlyturned endportions I5 of arack bar I6 to the piston heads. This rack barI6 therefore rigidly connects the head ends of the two opposed bellowspistons and is formed intermediate its ends with a series of openings I1to receive the teeth of a segmental gear I8 which is rigidly secured bya pin I8a to an operating shaft I9 mounted in suitable bearings in theopposed walls of the case I, said shaft extending transversely of thecase and of the rack bar I6 with one end of said shaft I9 projectingthrough its bearing member` 20 in the wall of the case for theattachment thereto of a windshield wiper indicated at 2| in dotted linesin Fig. v3, this wiper being of the usual construction mounted upon anarm 22 having a head by means of which it is detachably and adjustablysecured to the outer end of the shaft I9 in the usual manner, the end ofthe shaft being reduced in diameter and screwthreaded( as at 23 andformed adjacent said screwthreaded end with a tapered and ribbed portion24 to receive a similarly tapered and ribbed bore of the head of the arm22, so that by placing the head of the wiper arm in engagement with thetapered end portion 24 of the shaft I9 and then applying a nut to theouter screwthreaded end 23 of the shaft, the Wiper arm may be rigidlyand adjustably secured to the outer end of the shaft.

As shown in Fig. 3, the wall of the case I is formed with an opening 25to receive the end of a tubular conduit not shown, which conduit leadsto the intake manifold of the internal combustion engine so that asuction will be created through this conduit and through a passage 26formed in the wall of the case and opening at one end into the bore 25and at its opposite end through the outside surface of the wall of thecase. This passage 26 is in open communication at its outer end with apassage 21 extending through the wall of the case, the communicationbetween the outer end of these passages 26 and 21 being controlled by aslide valve or plate 28 resting against the outer surface ofA the casewall and provided with a depression or passage 29 adapted to affordcommunication between the passages 26 and 21 when the valve plate 28 isin raised position as shown in Fig. 3. 'I'he passage 21 opens atitsinner end directly through thev inner surface of the case wall andformed in this wall and opening through said inner surface thereof arevtwo passages 30 spaced laterally from the passage 21 and adapted tocommunicate with said passage through a passage 3l formed in a valveplate 32 adapted toy seat laterally against the inner surface of thecase wall and cover the inner ends of the passages 21 and 30.

This valve plate32 is formed with an elongated slot 33 through which theshaft I9 extends and said valve plate 32 is pivotally supported adjacentits lower end by means of a pivot pin 34 so that it may swing laterallyin contact with the surface of the case wall and thus by such swingingmovement laterally, bring the passage 21 into' communication through thepassage 3I with either one of the passages 30 which passages areextended in the casel wall longitudinally of the structure and open attheir outer ends into passages 35, each of which is in opencommunication at all times with the vacuum chamber-l| outside of eachbellows piston, each passage v3|) communicating at its outer end withone of Athe passages 35 through a suitable nipple or thimble 36 mountedin the end of the passage 30 and projecting through the flange 6 ontheinner end of the rubber bellowsv5. l

'Therefore when the valve slide 28 is in open position, that is,positioned with its passage 29 registering with the outer ends of thepassages 26 and 21, engine operation will create a suction through thesepassages and through the passage 3| in the valve plate 32 and thencethrough one of the passages 30 and within one of the vacuum chambers I Ithrough the open passage 35, de pending upon the position to which thevalve plate 32 is swung, suction being created through the passages 21and 30 to create a vacuum within the chamber II surrounding and at theend of the. left hand piston within the left hand cylinder when thevalve plate '32 is in the position shown in Figs. 1 and 5. When thisvalve plate is in this position, the inner end of the other passage 30lwill be uncovered by the valve plate as shown inv v Fig. 5 landtherefore the chamber outside of the I right hand piston will be in opencommunication -one of the bellows pistons externally, under vacuum andthe other externally, under atmospheric pressure, thus causing thepiston at one end to expand and the piston at the other end tocontract,- the two pistons being rigidly connected by means of the'rackbar I 6.

In this connection it will be noted that the por tion of the vacuumchamber II which surrounds the bellows is in open communication with theportion of the chamber at the end of the piston through the'spacesbetween the lugs I0 of the disk 9 which form the guides for the outerend of each piston and, therefore, full force and inuence of the vacuumis applied 'to the piston to cause it to expand in a longitudinaldirection. As vacuum force is applied exteriorly of the bellows wall ofeach piston and as the interior oi' each piston is subjected toatmospheric pressure, tendency of the bellows wall to collapseor toexpand radially is obviated.

It is most desirable that the valve plate 32 be shifted from oneposition to another to alternate the action of vacuum upon the pistonswith a quick snap action so that the direction of movement of the vtwobellows pistons and their connecting rack bar will be quickly reversedby a sudden movement of the valve as distinguished from a continuingmovement, and to give such quick movement a 4valve operating plate 31 ispivotally supported upon the shaft I9 to turn freely upon said shaft butis frictionally held against a shoulder I38 of said shaft by means of acoiled spring 39 mounted upon said shaft between a pair of washers 4Ione of which engages the side of the operating plate 31 and the other ofwhich engages the inner side of the valve plate 32. This spring 39 thusexerts a limited force to hold the member 31 in contact with theshoulder 38 and to also hold the valve plate 32 in contact with theinner surface of the case wall. The

swinging mevement of the valve plate s2 is limited 75 y lThis valveplate isthus limited in its swinging valve plate movement to registerits passage 3l with either one or the other of the passages 30. In alike manner, the valve control plate 31 is limited in its swinging,lateral movement upon the shaft I9 by means ofupwardlyextending arms 44adapted to engage the stop lug 43, and interposed between the valveplate 32 and the valve control plate 31 is a coiled spring 45'underlight compression, a seat for one end of said spring beingv providedadjacent the lowerV end of the valve control plate 31 y and a similarseat for the other end of said spring being provided upon the valveplate 32 above the pivot 34 of said plate and below the shaft I9, saidseats being proidded by turning portions of these plates laterally toform ears 46 and 41 against which the ends of the spring 45 are seated.The lower end of the valve control plate 31 extends within an open slot48 formed in one 'side of the rack bar I6 so that`upon longitudinalmovement of the rackv bar in either direction one of the ends ofthelopen slot 48 will come into contact with the lower end portion ofthe valve control plate 31 and'thus swing said plate upon its pivotalsupport on the shaft I9.

Referring particularly to Fig. 2 of the drawings, itwill be seen thatthe longitudinal axes of the shaft I9 and pivot pin 34 lie in the samevertical plane and that the open end of the passage 21 is also in thisvertical plane. The

-valve control plate 31 is mounted to swing on the shaft I9 and thevalve plate 32 is mounted to swing upon the pivot pin 34 with thepassage 3I at its upper end positioned to register with the inner openend `of the passage 21 so that upon lateral swinging movement of theplate 32' either one or the other of the passages 30 will be connectedby the passage 3| in the 4valve plate with the passage 21. With the'valve plate 32 and the valve control vplate 31 in the relative positionsshown in Fig. 2 and with the rack bar I6 moving in the direction of thearrow, the end of the slot 48 in said rack bar will come into tengagement with the lower end of the control plate 31 and swing "thisplate independently of the valve plate 32, but as the spring 45 isconnected or seated at its upper end upon the valve plate 32 arid at itslower end upon the lower end portion of the control plate 31, as thecontrol plates swing across the vertical plane of the lon- I8 and pivotpin-34, this spring 45 will exert a force upon the valve plate 32upwardly from its pivot 34 and as the lower end of said spring passessaid vertical plane, the direction of the force of said spring will beshifted from one side of said vertical plane to the other and this forcewill quickly swing the valve plate 32 to the position shown in Fig. 1,with a quick snap-over action, such -swinging movement being limited bythe lugs- 42 on the upper end of the valve plate and the swingingmovement of the control plate 31 will be limited by the lugs 44 upon itsupper end. Therefore upon movement of the rack ,bar in one direction, itwill be brought into engagement with the control plate 31 and swing thisplate in one direction to cause a quick shifting of the of vacuum uponthe bellows by such shifting of the valve plate 32, the direction ofmovement of the rack bar I6 will be reversed and the opposite end of theopen slot 48 therein will come Jqf 'the slide 2s 32, and upon reversalof the action.

into contact with the lower end of the valve control plate 31 and swingthis plate in the opposite direction to shift the valve plate A32 andreverse to the direction of operation of the bellows pistons.

With this arrangement of valve operating.

part an oscillatory movement to they shaft I9 and the windshield wiperconnected to its outer end.

The stopping and starting of the device is controlled by the valve slide28, this slidebeing operated by means of a pull and pushbar 49 having abearing within the side wall of the case I directly below the end of theshaft I9 which projects a limited distance through this wall and isprovided with a notch 50 in said end. The valve plate slide 28 is formedwith an opening I through which the projecting end of the shaft I9extends and this slide is also formed with a lug 52 projectingdownwardly within the opening 5I to engage within the notch 5II.l Theslide 28 is normally pressed downwardly with its lower end in contactwith the bar 49 bymeans of a coiled spring4 53, said spring being seatedat its Vlower end upon a sheet metal bracket 54 secured to and carriedby the upper end of the slide 28 and this spring is seated at its upper'end against a lug 55 projecting from the side of the casing wall I, anda similar lug 56 projects from said wall at a point below the pull andpush bar 49. The slide 28. and its operating spring 53 are en closedwithin a suitable sheet metal casing 51 and this casing has end angesformed into engagement with said lugs 55 and 56 to firmly secure saidcasing in p lace. The pull and push bar 49 extends through an opening inthe Wall of the casing 51 and past the lower end of the slide 28 andinto arbore in the wall of the case I, which bore forms a bearing forthe inner end of this bar 49, which end is formed with a notch 58 in itsupper side into which notch thelower end ofthe slide 28 is adapted todropwhen the bar is pulled outwardly; The pulling outwardly of the bar.49 permits the slide 28 to move downwardly and close off communicationbe- -tween the passages 28 and 21 this downward movement of the slidebeing eifected by the spring 53, the lower end of the slide riding downthe inclined outer end of the notch 58 until the lug 52 on the slideengages the shaft I9 and ythen,;when the notch 58 in the end of theshaft comes opposite said lug, said lug will dropl into the notch,completing the downward movement and holding the shaft I9 in theposition to which it has been turned. The notch 50 will be so positionedrelative to the position ofthe wiper larm 22 on the shaft `that thewiper will be held at one endof its stroke by the engagement of the lug52 with the notch 5|) in the end of the shaft. Preferably the outer endof the notch 58 will be inclined so that by an shape as shown in Fig. 4,so Athat when the wiper is inoperativefthe wiper arm may be swung ineither direction, manually, the shape of the lug and notch permittingrotation of the shaft I9 against the action of the spring 53. Also asshown, the spring 53 is preferably bowed intermediate its ends so thatone side thereofwill engage the outer wall of the enclosed casing 51 andsaid spring will therefore tend to forceV valve slide 28. laterally intoface engagement with the outer surface 'of the wall of the casing I toprevent leakagepast the slide.

Any suitable means may be provided for supporting thestructure inoperative position, the

. form of such supporting means being determined by the place ofapplication of the device in use, but as shown in the accompanyingdrawings where the device is to be mounted upon the header of awindshield, such attaching support is provided by a bail 59 the ends ofwhich are secured in any suitable manner, as by screw studs 6U, to theupper and lower sides ofthe case l, with said bail provided with anopening through which the'screw-threaded end portion. of the bearingmember projects, this bearing member being secured in any suitablemanner within an opening in a header of the windshield.

Obviously changes-may be made in the construction and arrangement ofparts without de-.-

parting from the spirit` of the present invention and such Vchanges arecontemplated.

Having thus fully described my invention what I claim is: A

1. In a windshield wiper motor operated from a source of suction, ahollow central casing with open ends, a pair of flexible-walledlongitudinallyextended bellows with'heads disposed outwardly in oppositedirections and with open inner ends connected respectively to the openends of said hollow central casing, vmeans for continuously maintainingthe interiors of said central casing land said bellows at atmosphericpressure, means operatively interconnecting the heads of-said bellowsfor eiiecting simultaneous reciprocation thereof in the-same direction,a pair of cylinders respectively enclosing said pair of bellows, a poweroutput shaft to which a windshield wiper is adaptedto be connected,mechanism operaselectively valving each of said cylinders alterl natelyto atmospheric pressure and to said source of suction respectively, saidvalving means and said mechanism being disposed substantially entirelywithin the interiors of said central casing -andsaid pair of bellows,whereby said bellows and said cylinders form with said casing adoublewalled vchamber adapted to muilie the operating noise of said`valving means and 'said mechanisni contained therein.

2. In a windshield'wiper motor operated from a source of suction, ahollow central casing with.

open ends, a pair of flexible-walled longitudinallyextended bellows withheads disposed outwardly in opposite directions and with open inner endsconnected respectively to the open ends of said hollow central casing,means for continuously maintaining` the interiors of said central casingand saidbellows at atmospheric pressure, means operativelyinterconnecting the heads of' said bellows for effecting simultaneous.reciprocation thereof in the same direction, a pair of cylindersrespectively enclosing said pair of bellows, a power output shaft towhich a windshield wiper is adapted to be connected, mechanismoperatively connecting said head-interconnecting means with said outputshaft for transmitting the motion of said bellows thereto, meansoperatively connected tosaid mechanism and responsive to thereciprocation of said bellows for selectively valving each of saidcylinders alternately to atmospheric pressure and -to said source ofsuction respectively, lsaid' valving means and said mechanism beingdisposed substantially entirely within the interiors of said centralcasing and said pair of bellows, whereby said bellows and said cylindersform with said casing a double-walled chamber adapted to muiiie theoperating noise of said valving means and said mechanism cont'ainedtherein, the sides oi' each bellows being spaced apart from the adjacentcylinder wall by a substantial clearance, and spaced guide membersconnected to said bellows and extending across said clearances intoguiding engagement with said cylinder walls.

3. A device for the purpose described including a central casingproviding a chamber and having a. wall formed with air passages certainof whichV open through the opposite faces of the wall, opposed cylinderssecured to opposite sides of the casi-ng, a bellows within each cylinderhaving a flexible circumferential wall with said lexible walls 'spacedfrom the walls of the cyl-l inders to form a vacuum chamber in eachcylinder between said cylinder and its bellows, said ilexible wall ofeach bellows being extended at its inner end to close the inner end ofeach vacuum chamber in each cylinder, certain oi' the passages in thel,Wall of the casing opening into said vacuum chambers to permit thewithdrawal of air therefrom, a valve plate within the casing inengagement with the inner face of the wall thereof to controlcommunication between the'passages in the wall, a control member Withinthe casing and operatively connected with said valve plate to move thesame upon movement of said control member, means secured to and movablewith said both bellows and connecting the samegfor simultaneousmovement, said means extending through the chamber of the casing andadapted to engage and move said control member upon movement of saidbellows in either direction, means within the chamber of the casing fortransmitting motion from said means connecting said bellows, a valveslide to of said slide.

` ARTHUR J. RICHARDS.-

Ymoved to bring said notchopposite the lower end

